Thyroglobulin
Thyroglobulin is a protein made only by thyroid tissue and used to produce thyroid hormone. Measuring it reflects the amount of thyroid tissue present in your body.
Because thyroglobulin comes specifically from thyroid cells, it is most valuable as a tumor marker in people monitored after treatment for certain thyroid cancers. Rising levels after thyroid removal can prompt further evaluation. It is not used as a general thyroid function screen.
A high or rising thyroglobulin, particularly after thyroid cancer treatment, may prompt your clinician to look for remaining or recurring thyroid tissue. Levels can also rise with benign thyroid conditions like goiter or inflammation. Interpretation depends heavily on your clinical history.
A low or undetectable level after treatment for thyroid cancer is often a reassuring sign that little thyroid tissue remains, though results must be read alongside thyroglobulin antibodies.
There is no single universal target, since interpretation depends on whether you still have a thyroid and your treatment history. Your clinician tracks trends over time rather than a fixed number.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.